The Influence Of GTR Membrane Combined With Root Conditioner On The Bone Coverage Of The Exposed Root Surface Near The Alveolar Cleft

PURPOSE: To explore the method of establishing a rat model of alveolar cleft with exposed root surface and to evaluate the effect of GTR membrane combined with root conditioner on the bone coverage of the exposed root surface near the alveolar cleft on this rat model.METHODS: Standard maxillary alveolar cleft were established unilaterally on six male SD rats aged 8 weeks.Then curets were used to eliminate the bone on the mesial root surface of maxillary second molar,thus exposing the root surface.Three rats were executed 4 weeks and the other three 8 weeks postoperatively.Micro-CT was used to evaluate the root exposure.Alveolar cleft with exposed root surface were created bilaterally on twelve male SD rats aged 8 weeks as stated and were conducted alveolar bone graft afterwards.According to the way of treatment,twelve rats were randomly divided into three groups as root conditioner group,GTR membrane group and GTR membrane combined with root conditioner group.Twelve rats were executed 8 weeks postoperatively and Micro-CT was used to evaluate the regenerated new bone volume and the coverage of exposed root surface.RESULTS: The volume of regenerated new bone at the experimental side was significantly smaller than the control side both 4 weeks and 8 weeks after the surgery.The height of the exposed root surface at the experimental side was significantly higher than the control side both 4 weeks and 8 weeks after the surgery.8 weeks after bone graft,the volume of regenerated new bone at the experimental side was significantly larger than the control side in all three groups and the ascending order is root conditioner group,GTR membrane group and GTR membrane combined with root conditioner group.8 weeks after bone graft,the height of the exposed root surface at the experimental side was significantly lower than the control side in GTR membrane group and GTR membrane combined with root conditioner group and the descending order is root conditioner group,GTR membrane group and GTR membrane combined with root conditioner group.There is no interaction effect between root conditioner and GTR membrane on the regenerated new bone volume and the coverage of exposed root surface through factorial design.CONCLUSION: A rat model of alveolar cleft with exposed root surface was successfully established.Root conditioner,GTR membrane and the combination of them can enhance regenerated new bone volume and the coverage of exposed root surface.